当x=-1 y=1/2 求多项式2(x-2y)²-4(2x-y)+(x-2y)²-3(2x-y)的值
当x+y/x-y=1/2时,求代数式x-y/x+y-2x+2y/x-y的值
当x=1/2,y=1/3时,求代数式x-(x+y)+(x+2y)-(x+3y)+…-(x+101y)的值
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
当x=2,y=-1时,求代数式(x+y)(x-y)+(x-y)²-(x²-3xy)的值
当x=-1,y=-2时,求整式(2x-y)(2x+y)+(2x-y)(y-4x)+(y-3x)²的值 快
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
当2x-y/x+y=3时,求代数式2x-y/2x+2y+x+y/6x-3y的值.
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
已知4x=9y求(1)x+y/y (2)y-x/2x
已知3x-4y/2x+y=1/2 求x/y的值